الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Basal cell carcinoma (BCC) of the skin is the most common type of human cancer, representing more than one-third of all cancers. BCC occurs most frequently on the head, neck, and other chronically sun-exposed regions of fair-skinned persons in the fourth decade of life and later. BCC is a low-grade tumor with a low potential for metastasis but with a significant risk of local invasion, destruction, and recurrence. Thus, although the mortality from BCC is low, the morbidity is high. Chronic solar exposure, a source of mutagenic ultraviolet radiation (UVR), is the most important etiologic factor identified in most cases of BCC. The subsequent molecular genetics steps in the pathogenesis of BCC, however, are poorly understood. The manifestation of BCC is most frequently nodular; the second most frequent clinical manifestation is a superficial spreading form A third clinical variant is the sclerosing or morphemic form, which is characterized by sclerosing, cicatricial, badly circumscribed lesions of white or yellow color. These tumors are flat and their manifestation depends on the size of the fibrotic component. BCC lesions may sometimes be pigmented. Biopsy or surgical excision of the lesion provides the specimen for histopathological examination, which is the mainstay for diagnosis.
The most common and available treatment for BCC is surgical excision. Mohs Micro graphic surgery allows tumour removal by a smaller margin while ensuring a cure rate of up to 99%. The term Mohs micrographic surgery
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encompasses staged serial excision and histological examination of the lesion margin, so it enables the surgeon to have control of the entire tissue margin and re-excision of microscopic tumor extension if present In most cases the defect does not close directly and it is necessary to reconstruct the defective tissues using local or regional or distant (free) flap or skin graft. Local flaps are the main concern in facial reconstruction. Local flaps are the commonest to be used.